The main objective of this section is to provide an introduction to the Thermo-hydraulic Design, Mechanical Design and Operating Considerations of Shell & Plate Heat Exchanger (SPHE). This type was considered a “hybrid” thermal exchanger, positioned between a traditional plate-and-frame heat exchanger (PFHE) with gaskets and a shell-and-tube heat exchanger (STHE), which combines the efficiency of the plates with the solidity of the shell that encloses the tubular elements. Thermo-hydraulic design with correlations single-phase heat transfer and pressure drop with comparison of the results of different authors are described with details on pressure drop in the channels, ports, and collectors and evaporation/condensation, including fouling resistance values for different flow velocities in tubular (HEs) and PHEs. Basic elements such as geometry of plate, thermal mixing, and plate arrangements have been discussed taking into consideration the fatigue resistance, weld quality, and fatigue-resistant design. Construction material details are described (plates can be made of austenitic steels, nickel materials, nickel alloys and titan materials) and the manufacturing process is step by step listed with video link. In the industry, SPHEs have a broad range of applications such as chemical processing, oil and gas production, petrochemicals, refining, power generation, renewable energy, revamps, marine, refrigeration, HVAC, and geothermal energy. The usage of SPHEs in various industrial applications come with distinctive advantages. In gas dehydration, the SPHE leads to more efficient energy recovery and reduction in the size of other heat exchangers in the system. Moreover, the welded-type SPHE leads to more compact designs.

1. INTRODUCTION

In general, plate heat exchangers (PHEs) have a lot of advantages. They have a high number-of-transfer-units (NTU) value due to countercurrent flow. They are flexible in design and allow for a large range of capacities. They are easily accessible for maintenance (except the fully welded types). They have a high compactness of the heat transfer surface area. The cost can be low due to less or no welding and the possibility of multiple duty operation by means of assembling multiple heat exchangers together. Fouling can be limited due to self-cleaning caused by highly turbulent flows. The disadvantages are the lower design pressures and the use of gaskets leading to temperature and working fluid constraints. High pressure drops can occur if low-density vapors at high flow rates are used.

At the end of the 1980s, Frost & Sullivan market research put forward the shell and plate heat exchanger (SPHE). This type was considered a “hybrid” thermal exchanger, positioned between a traditional plate-and-frame heat exchanger (PFHE) with gaskets and a shell-and-tube heat exchanger (STHE), which combines the efficiency of the plates with the solidity of the shell that encloses the tubular elements.

The first commercial SPHE was produced by the Vahterus Oy Company in the 1990s and is now manufactured by various major PHE manufacturers. A SPHE with inspectable welded plates represents the classic example of hybrid equipment, combining the advantages of the plate heat exchangers (high efficiency) with those of STHEs (high working pressure). In the past, STHEs were the preferred choice for applications involving high pressures, temperatures, or both. More recently however, SPHEs proved themselves suited to pressures up to 400 bar and temperatures up to 900°C. SPHEs combine the pressure and temperature capabilities of a cylindrical shell with the excellent heat transfer performance of a PHE. The round plates ensure an even distribution of mechanical loads, without the stress concentrations that occur in the corners of rectangular plates. The approximate heat transfer area compactness of SPHEs is 300 m²/m³; whereas, this value for STHEs is ≤ 100 m²/m³. Because the typically high U-values are inherent to PHEs, multiple folds of size reduction can be achieved with SPHEs when compared to STHEs. The PHEs can be categorized by construction, as shown in Fig. 1.